diff --git a/django/sp_sso/invite/forms.py b/django/sp_sso/invite/forms.py
index 01eb5e9..5176ddd 100644
--- a/django/sp_sso/invite/forms.py
+++ b/django/sp_sso/invite/forms.py
@@ -37,12 +37,19 @@ class InvitationForm(forms.Form):
                 self.fields[prefilled_field].widget.attrs['readonly'] = True
 
         etablissement_code = kwargs['initial'].get('hote_etablissement')
-        self.fields['hote_etablissement_description'].initial = ldap_get_description_etablissements(etablissement_code)
-        self.fields['hote_etablissement_description'].widget.attrs['readonly'] = True
+        self.fields['hote_etablissement_description'].initial = \
+                ldap_get_description_etablissements(etablissement_code)
+        if not self.fields['hote_etablissement_description'].initial :
+            self.fields['hote_etablissement_description'].initial = etablissement_code
+        else:
+            self.fields['hote_etablissement_description'].widget.attrs['readonly'] = True
 
         unite_code = kwargs['initial'].get('hote_unite')
         self.fields['hote_unite_description'].initial = ldap_get_description_unites(unite_code)
-        self.fields['hote_unite_description'].widget.attrs['readonly'] = True
+        if not self.fields['hote_unite_description'].initial:
+            self.fields['hote_unite_description'].initial = unite_code
+        else:
+            self.fields['hote_unite_description'].widget.attrs['readonly'] = True
 
     # Blank-seperated list of recipient email adresses
     email = forms.CharField(